The couple who found the tiger called authorities to report what they had seen, and police said they were initially unsure if the animal was real or if they might be hallucinating.
Although the tiger, which appeared to be well fed, was cooperative, it was tranquilized for the trip across town to the BARC campus, which is mostly used for dogs, cats and occasional farm animals, Cottingham said.
The garage, which is in a home southeast of central Houston, was secured only with a screwdriver and a nylon strap, the station reported.
"He's in a rinky-dink cage that could easily bust open", an officer said, according to KHOU 11.
The tiger was tranquilised and transported to the city's BARC animal shelter, Lara Cottingham, chief of staff of Houston's Administration and Regulatory Affairs Department, told USA Today.
Houston animal control officials would like to know who owns a "perfectly delightful" tiger that turned up unexpectedly in a little used house in a residential part of the city.
It is unclear what charges the owner of the house may face now.
The shelter, which takes in more than 26,000 animals each year, is still trying to find a long-term facility to take the tiger.
"It's big and it's scary", said neighbor Pablo Briagas.
'It was a pretty small cage inside basically a garage in a house that didn't look like it was in the best shape. "My kids. the neighbor has kids, so, it's scary". If the owner is ever located, she or he faces stiff fines.